# Case Study on the Genetic Parameters and Possibilities of Selecting Gilts for Traits Monitored in the Performance Test

## TL;DR

This study estimates genetic parameters for traits in gilts to improve pig meat production through selective breeding.

## Contribution

The study provides new heritability estimates for key traits in gilts in Serbia, supporting data-driven breeding decisions.

## Key findings

- Heritability coefficients of 0.37 for BF1 and 0.35 for BF2 indicate high genetic potential for these traits.
- The heritability coefficient for MLD is 0.23, suggesting it is a medium heritability trait.
- Direct genetic effects accounted for 0.2647 of the total variation in age at the end of the test.

## Abstract

In the Republic of Serbia, selecting gilts for breeding is mostly based on their phenotypic characteristics. Because the estimation of breeding value is not done systematically, genetic parameters remain unknown although it is well known that a genetic improvement of high heritability traits in gilts can be achieved relatively easily by selection of these traits. Thus, it is important to precisely estimate heritability coefficients of economically important traits monitored in a performance test of gilts. This is essential since the effect of selection depends on the precision of estimation of heritability coefficients. Effects of selection are directly proportional to the accuracy of estimation of breeding value i.e., the estimation of heritability coefficients which precede. These findings highlight the importance of the estimation of variance components for production traits of gilts and consequently their effect on genetic improvement of economically important traits in the pig meat industry.

This research examined the phenotypic and genotypic variability of traits assessed in the gilt performance test and their subsequent impact on gilt selection. The traits evaluated in the gilt performance test were analyzed on two pig farms over a period of 3 consecutive years. A total of 3664 gilts were included in the research. At the end of the test, body weight, backfat thickness (BF1 and BF2), and longissimus dorsi muscle depth (MLD) were measured using an ultrasound device. The following breeds were evaluated on the farms: Landrace (L)–1981 gilts, Large White (LW)–1344 gilts, and Duroc (D)–339 gilts. In the analyzed population, direct genetic effects accounted for 0.2647 of the total variation in age at the end of the test (AET). Heritability coefficients of 0.37 for BF1 and 0.35 for BF2 indicate that these traits are highly heritable in the studied population. On the other hand, the heritability coefficient for the depth of MLD, which is 0.23, places this trait in the group of medium heritable traits. High heritability coefficients of these traits indicate great potential for genetic improvement through selection. The use of well-designed selection programs aimed at these traits can significantly accelerate the genetic improvement of the population and have an impact on the economic profit of pork production.